| Abstrakt: |
Melon (Cucumis meloL.) is one of the main vegetable crops produced in the Brazilian Northeast region. However, despite the favorable climate for its development, melon is still affected by diseases, including foliar diseases such as powdery mildew (Podosphaera xanthii(Castag.) U. Braun & N. Shish.). This study aimed to determine the efficacy of alternative products (less aggressive to man and nature) for managing powdery mildew in melon. A randomized block design (RBD) was used in the experiment, with eight treatments and eight replications. Four fertilizers (Agro Mos®, Copper Crop®, Soil Set®, and Fertisilício®), the biocontrol product Suppress-L™, and raw milk (20%) were tested compared to a nontreated control and the fungicide Amistar Top®. The following variables were analyzed: incubation period (IP), disease incidence (INC), disease severity (SEV), the area under the disease progress curve (AUDPC), and melon growth variables (plant height, stem diameter, number of leaves, leaf area, physicochemical quality of fruits, and biochemical analysis of fruit). The data were subjected to analysis of variance (ANOVA), followed by mean comparison by the Scott-Knott test at 5% probability. Raw milk was the best alternative control method for powdery mildew and was as effective as chemical control (Amistar Top®), reducing the SEV by 49% and increasing the °Brix of melon by 19%. Copper Crop® was also effective in controlling powdery mildew and reduced SEV by 30%. The present study highlighted that the activities of polyphenol oxidase, peroxidase, chitinase, and β-1,3-glucanase are involved with the melon defense mechanism since the treatments with higher enzymatic activities promoted lower powdery mildew severity. Among the studied products, raw milk promoted the highest activities of the studied enzymes. |
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